The present invention relates to an endoscope system for processing a video signal formed by means of a solid-state image sensing device, and then displaying the processed signal on a screen of a monitor television or the like, for observation.
Endoscopes of various types are conventionally used in endoscope systems which are designed so that an insertion section is inserted into the human body cavity for observation of the inner body wall. Optical endoscopes, i.e., the so-called fiberscopes, have hitherto been used more frequently than endoscopes of any other types. The fiberscopes comprise a slender, flexible insertion section, which is adapted to be inserted into the body cavity, and a handy-control section coupled to the insertion section. As is generally known, the distal end portion of the insertion section is provided with an objective lens, a light guide and an image guide, each formed of a bundle of fibers, a waterfeed/suction port, a suction/forceps port, etc. The tilt angle of the distal end portion is adjustable. The control section includes control means for controlling gas or water feed, and adjusting means for angle adjustment of the distal end portion. According to these fiber scopes, the insertion section is inserted into the body cavity, and an optical image of a desired region, formed by the objective lens, is guided through the image guide to an eyepiece portion of the control section. The condition of the inner wall of the body cavity can be observed macroscopically through an optical lens at the eyepiece portion. The light guide is connected to a light source, and serves to illuminate the body wall for a clear view.
A novel technology has recently been developed in the field. According to this method, a video camera is mounted on the eyepiece portion of the optical endoscope, and a video signal, produced by a solid-state image sensing device of the camera, is transmitted to a video-signal processing unit. The signal received by the processing unit is processed thereby, and the condition of the desired region of the body wall is displayed on a monitor television or is recorded by means of a recorder. The on-off control of the recording operation and the like are performed by operating control switches on the recorder, which is situated at a distance from the fiber scope. The control switches should be operated by an assistant.
In a known endoscope of another type, a solid-state image sensing device is provided directly on the distal end of its insertion section. This endoscope is of an electronic-observation type, constructed so that the desired region of the inner body wall is illuminated with a light from a light source, guided through a light guide at the distal end portion of the insertion section. A video signal produced by the image sensing device, receiving the reflected light from the body wall, is transmitted to a video-signal processing unit. The processing unit can process the received video signal, and reproduce it on a monitor television or record it by means of a recorder. This electronic endoscope, unlike the fiberscope, is not adapted for macroscopic observation of the optical image which is indicative of the body wall. In the electronic endoscope, moreover, the on-off control of the recording operation and the like can be performed by operating control switches arranged on the side of the recorder. Also, an operator himself can execute the control by operating remote control switches, which are mounted on the handy-control section of the endoscope.
When using the optical endoscope with the video camera on the eyepiece portion of its handy-control section, the operator must operate the control switches on the recorder, remote from the endoscope, in order to effect the necessary operations, such as recording. Such a switching operation is very troublesome for the operator who is in charge of a medical examination. When the assistant operates the switches under instructions from the operator, there would inevitably be an time lag between the instructions and the operations by the assistant. In such a situation, it is very difficult for the operator to record a desired image of a desired region of the inner body wall.
When using the electronic endoscope, on the other hand, the operator himself can directly operate the control switches at the handy-control section, so that he can record his desired image with ease.
In most cases, the endoscopes of the two types, electronic and optical, are used alternatively at the request of one and the same operator.
However, the control switches are mounted on the handy-control section in the case of the electronic endoscope, and on the side of the recorder in the case of the optical endoscope with the video camera on its eyepiece portion. When alternately using the endoscopes of these two types, therefore, there is a difference in switching capability between the endoscopes which are used similarly with a monitor television for observation. Thus, the operator may get confused while operating the switches, thereby lowering the operating capability of the endoscope system.